From: Arnd Bergmann <arnd@kernel.org>
To: Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>,
Eddie James <eajames@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Al Viro <viro@zeniv.linux.org.uk>,
linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] hwmon: occ: fix unaligned accesses
Date: Tue, 10 Jun 2025 11:25:49 +0200 [thread overview]
Message-ID: <20250610092553.2641094-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Passing a pointer to an unaligned integer as a function argument is
undefined behavior:
drivers/hwmon/occ/common.c:492:27: warning: taking address of packed member 'accumulator' of class or structure 'power_sensor_2' may result in an unaligned pointer value [-Waddress-of-packed-member]
492 | val = occ_get_powr_avg(&power->accumulator,
| ^~~~~~~~~~~~~~~~~~
drivers/hwmon/occ/common.c:493:13: warning: taking address of packed member 'update_tag' of class or structure 'power_sensor_2' may result in an unaligned pointer value [-Waddress-of-packed-member]
493 | &power->update_tag);
| ^~~~~~~~~~~~~~~~~
Move the get_unaligned() calls out of the function and pass these
through argument registers instead.
Fixes: c10e753d43eb ("hwmon (occ): Add sensor types and versions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/hwmon/occ/common.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 9029ad53790b..b3694a4209b9 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -459,12 +459,10 @@ static ssize_t occ_show_power_1(struct device *dev,
return sysfs_emit(buf, "%llu\n", val);
}
-static u64 occ_get_powr_avg(u64 *accum, u32 *samples)
+static u64 occ_get_powr_avg(u64 accum, u32 samples)
{
- u64 divisor = get_unaligned_be32(samples);
-
- return (divisor == 0) ? 0 :
- div64_u64(get_unaligned_be64(accum) * 1000000ULL, divisor);
+ return (samples == 0) ? 0 :
+ mul_u64_u32_div(accum, 1000000UL, samples);
}
static ssize_t occ_show_power_2(struct device *dev,
@@ -489,8 +487,8 @@ static ssize_t occ_show_power_2(struct device *dev,
get_unaligned_be32(&power->sensor_id),
power->function_id, power->apss_channel);
case 1:
- val = occ_get_powr_avg(&power->accumulator,
- &power->update_tag);
+ val = occ_get_powr_avg(get_unaligned_be64(&power->accumulator),
+ get_unaligned_be32(&power->update_tag));
break;
case 2:
val = (u64)get_unaligned_be32(&power->update_tag) *
@@ -527,8 +525,8 @@ static ssize_t occ_show_power_a0(struct device *dev,
return sysfs_emit(buf, "%u_system\n",
get_unaligned_be32(&power->sensor_id));
case 1:
- val = occ_get_powr_avg(&power->system.accumulator,
- &power->system.update_tag);
+ val = occ_get_powr_avg(get_unaligned_be64(&power->system.accumulator),
+ get_unaligned_be32(&power->system.update_tag));
break;
case 2:
val = (u64)get_unaligned_be32(&power->system.update_tag) *
@@ -541,8 +539,8 @@ static ssize_t occ_show_power_a0(struct device *dev,
return sysfs_emit(buf, "%u_proc\n",
get_unaligned_be32(&power->sensor_id));
case 5:
- val = occ_get_powr_avg(&power->proc.accumulator,
- &power->proc.update_tag);
+ val = occ_get_powr_avg(get_unaligned_be64(&power->proc.accumulator),
+ get_unaligned_be32(&power->proc.update_tag));
break;
case 6:
val = (u64)get_unaligned_be32(&power->proc.update_tag) *
@@ -555,8 +553,8 @@ static ssize_t occ_show_power_a0(struct device *dev,
return sysfs_emit(buf, "%u_vdd\n",
get_unaligned_be32(&power->sensor_id));
case 9:
- val = occ_get_powr_avg(&power->vdd.accumulator,
- &power->vdd.update_tag);
+ val = occ_get_powr_avg(get_unaligned_be64(&power->vdd.accumulator),
+ get_unaligned_be32(&power->vdd.update_tag));
break;
case 10:
val = (u64)get_unaligned_be32(&power->vdd.update_tag) *
@@ -569,8 +567,8 @@ static ssize_t occ_show_power_a0(struct device *dev,
return sysfs_emit(buf, "%u_vdn\n",
get_unaligned_be32(&power->sensor_id));
case 13:
- val = occ_get_powr_avg(&power->vdn.accumulator,
- &power->vdn.update_tag);
+ val = occ_get_powr_avg(get_unaligned_be64(&power->vdn.accumulator),
+ get_unaligned_be32(&power->vdn.update_tag));
break;
case 14:
val = (u64)get_unaligned_be32(&power->vdn.update_tag) *
--
2.39.5
next reply other threads:[~2025-06-10 9:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-10 9:25 Arnd Bergmann [this message]
2025-06-10 20:52 ` [PATCH] hwmon: occ: fix unaligned accesses Guenter Roeck
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